This invention relates to an electronic tuning device of the type used for tuning musical instruments or in training music students. My prior U.S. Pat. No. 2,924,776 issued Feb. 9, 1960 describes one such tuning device in the form of an audio frequency pitch standard that is capable of producing accurately pitched sounds from all of the notes of a musical scale over a range of many octaves. Another tuning device employes a stroboscope to provide a visual comparison of the pitch of a musical note picked up by a microphone, with a stroboscope disc revolving at a speed determined by an accurate frequency standard. Such an instrument is shown in U.S. Pat. No. 2,806,953 issued to S. L. Krauss on Sept. 17, 1957. The present invention applies to improvements in the type of devices mentioned.
It is one object of the present invention to provide an improved tuning device having greater accuracy and stability than those previously known. It is another object of the invention to provide an improved tuning device that can operate an audio frequency pitch standard for audible comparison with an instrument to be tuned or that alternately or simultaneously can be used with a stroboscopic or other visual readout device. These and other objects of the invention will become apparent from the description which follows.